Strange aspect ratio on converted Cave carts

[Blander]

Hello!

I've been looking for an answer to this on my own, but I'm a bit of a noob when it comes to screens and resolutions and all that wondrous tech-y arcade stuff, so I apologize if the answer to this should be obvious.

I have a PGM and some Cave conversions, and am currently trying to optimize my display output for a cabinet I'll be building in the near future. I noticed while doing this that the Cave carts seem to output with black padding on all sides, even when the aspect ratio on my monitor is set to 4:3. My setup at the moment is PGM -> supergun (Mak Strike v3) -> OSSC (line 4x) -> LCD monitor. I'm attaching a couple images I've taken of this. The images show the games with the monitor display in 16:9 (I'd post 4:3, but my PGM seems to have up and died between me realizing the issue and creating this thread ), but you can still see the padding on the sides, which is still present when the monitor is on 4:3 and makes the image smaller than it probably should be. Is this how these are meant to output? Or is there something I need to do to get these to upscale properly and fill the entire available screen real estate? Is this a problem with the PGM itself (this would be nice, as I've already ordered a replacement...)?

If anybody could give me a push in the right direction, I'd be very thankful!

 

[gray117]

...Only just started looking at this myself. (was using doj - should be the same)

Done on latest firmware (0.90a) since a lot of options I saw people mentioning didn't seem quite the same/available on my older firmware... so might be worth updating if any of this doesn't make sense vs your menu.

If 5x works for you (or at least this version if you can navigate blind) the easy one for me was to:

settings otp>reset settings (in case you've tweaked anything)
(kind of working in reverse here for output opt.)
Output opt> Lines 5x format = 1920x1200
[Output opt> Line 5 x mode = Generic 4:3]
Output opt> 240p/288p proc = Line5x

Sampling opt> Allow TVP HPLL2x 'On'

[Adv. timing 1600x240 - adjust back porches for centering? maybe others for minor tweaks, but tbh seemed pretty good off the bat?]

(Assuming this works)
Settings opt> <Save profile> [1? or whatever]
****
Next easiest one for me was 3x

settings otp>reset settings (in case you've tweaked anything)

Output opt> 240p/288p proc = Line3x
[Output opt> Line 3 x mode = Generic 4:3]

Sampling opt. > <Adv. timing> 960x240 >
{Basically main adjust was sample rate and H active to pull out the horizontal [ignoring rotation ] }
H. samplerate 1302 (this was super sensitive)
H syncelen 15
H backporch 230
H active 940
V Synclen 3
V Back porch 13
V active 240
Sampling phase 180

****

Hope this helps... going to look at some of the formula based approaches --- hopefully science is better than punching the remote

 

[Blander]

Wow, thanks so much for this! Unfortunately I'm still waiting on my replacement PGM, so I can't try these settings at just this moment, but will do so as soon as it arrives! I did also find this post here after making this thread, so there might be something worth mining in there: https://videogameperfection.com/forums/topic/ossc-for-pcbs/ (Apologies if I'm preaching to the choir )

Will post an update when I have something!

 

[twistedsymphony]

I run my stuff on CRT so I don't have any experience using any of the scaling equipment you guys are using however the PGM outputs at a resolution of 448x224

You might notice that this doesn't make for a nice 4:3 aspect ratio, which is correct because the game is essentially designed around rectangular pixels, not square ones. So to make this scale properly you'd be looking at scaling the vertical and horizontal at different rates.
on a 1080P display you'd be looking at a x4.82 vertical multiplier and x3.21 horizontal multipler (assuming a horizontal screen)
on a 4K display you'd be looking at a x9.64 vertical multiplier and x6.43 horizontal multipler (assuming a horizontal screen)

if you padded the original image out with black-space to 480x240 and then did a 9x vertical multipler and a 6x horizontal multipler it'd be perfect on a 4K but would also have black bars on all sides. But you're on your own as to how that's accomplished with your scaling equipment

 

[gray117]

Yeah similar ... hooked it up once, found it was odd, and just left pgm hooked up to my crt instead ... but curiosity got me and had meanwhile swapped my main desk screen for a 4k one on an arm that could rotate.... so eventually had to give it another go!

And yeah the OSSC is really rather different from anything with a frame buffer, so it's more how the signal is constructed than something like an image scaler, and then quite a bit of luck how your screen interprets some of the output. And these games do seem to cause it a bit of an issue. However, despite some initial annoyance I ended up getting some seemingly excellent results using those settings - felt great to play... honestly probably going to prefer it this way.

I can see why some people may combine the OSSC with another device for ease in adjusting the image and/or to help provide a more standard signal to their screen ... at least until whatever the OSSC pro is comes out!

There is a bit of space top and sides for me using those settings for near optimum scaling to prevent 'shimmer' on scolling backgrounds, but the ratio looks pretty bang on for me with those settings and my screen (samsung UEAU9000 thingy) - mileage may well vary depending on screens, and there is apparently a more scientific way of attempting it ... But step 1 so far was just to noodle with it for a couple of hours ... well maybe more than a couple of hours, maybe more like double including a loop or two

And there didn't seem to be too many other posts about pgm + ossc, so having stumbled on this one I'd thought I'd chip in.

Will have to try it on some more screens + have a look at some other combos/settings. Let me know if you bump into any other cool settings!

Good luck!

P.S. there was also this one where the same guy got a good setting for espgaluda... didn't *seem* to do the trick for me but I did this first so was still figuring out the menus ... I'll try it again in combo with a clean setting reset (took me a while before I started using that to go back to 'stock' - doh!) and maybe some other settings (but yeah so much of this might just be depending on luck with screen performance too) :
https://videogameperfection.com/forums/topic/ossc-general-help-w-pixel-perfection/page/2/